Ask Marianne: Begonias need a head start in the cozy indoors

By MARIANNE BINETTI, SPECIAL TO THE P-I

Published
9:00 pm PST, Friday, March 17, 2006

Q: How should I start my begonia bulbs indoors? I saved last summer's plants by bringing them indoors for the winter. I cut back the stems in December as they turned into very ugly houseplants. Now I have three bulbs that show pink buds.

-- H.H., Renton

M.B.: Begonias should be started indoors now if you want them blooming by June. They need quick-draining soil to get started, but then prefer a soil that holds more water once they're well-rooted.

Fill a shallow tray or pot with moist peat moss or a lightweight, seed-starting soil mix. (A quick way to moisten dry peat moss or packaged soil is to use warm water.) Next, set the flattened bulbs into the mix so that the bottom half is buried, but the top half with the pink buds is sitting above the soil. Keep the soil moist but not wet in a bright, warm room.

Once those buds sprout into new growth that is 3 inches tall, you can transplant them into pots using a regular potting soil with a handful of extra peat moss or compost. Fertilize every two weeks with an all-purpose liquid plant food, but avoid getting the leaves or stems wet.

Do not set these baby begonias out until late May, when the nights have warmed up.

Q: I'm hoping you can settle a debate I am having with my family. We all love the colorful peppers. I say each color is its own special plant. They say that all peppers start out green and, if left alone, will ripen into the three different colors.

-- Ignorant in Sammamish

M.B.: You both win on this hot topic. Some peppers, such as the banana pepper and golden bell pepper, start out green and turn yellow when fully ripe. The Northstar pepper goes from green to deep red. Then there are the Purple Beauty Peppers. They begin green, turn purple and finish a deep red. A variety called Chocolate Beauty goes from green to dark brown, but it doesn't taste like chocolate.

In case you think green just means unripe, consider the Black Hungarian pepper. It has black young fruit that ripens to red, and the Marbles pepper first turns yellow, then purple, orange and finally flame red.

Q. I carefully dug up my dahlia tubers in the fall and placed them in plastic bags inside my insulated garage. I just checked on them to find a smelly mush of rotting dahlias. What do you think I did wrong?

-- P., e-mail

M.B.: Did you allow the dahlia tubers to dry out for a day or two before storing them away? Placing bulbs in a plastic bag while they are still damp is like wearing wet gym shoes all winter long -- the fungi can't help but multiply.

I like to use brown paper bags for overwintering tender bulbs, because they trap less moisture than plastic bags and you can write on them, so you can remember what's inside.

Many years dahlias can be overwintered in the ground simply by cutting back the plants and then covering the area with sword-fern leaves or some other waterproof material to keep the rain out. But last month it was so cold that I'll be surprised if any dahlia was able to pull off the death-defying feat. This is a great year to start fresh with new dahlias.